Artificial leg



Ime/706018' (Model.)

P. 0. PORTER.

ARTIFICIAL LEG. No. 417,588. Patenteane. 17, 1889.

UNITED STATES PATENT OEEICE.

PHILIP CHESTER PORTER, OF BERK'LEY, MASSACHUSETTS.

ARTIFICIAL LEG.

SPECIFICATION forming part of Letters Patent No. 417,583, dated December 17, 1889.

Serial No. 313,019. (Model.)

To all whom t may concern,.-

Be it known that I, PHILIP CHESTER POR- TER, a citizen of the United States, residing at Berkley, in the county of Bristol and State of Massachusetts, have Ainvented a new and useful Artificial Leg, of which the following is a specification.

My invention relates to improvements in articial legs which employthe longitudinal rigidity of wood as a support for the body; and the objects of myimprovements are, first, to provide a `leg which shall conform accurately to the irregularities of surface of each individual stump, securing a perfect fit in place of the approximate iit secured by carving; second, to provide a leg which shall, be proof against the internal lateral pressure consequent upon walking and against liability to split or crack, and hencemuch more -durable than the wooden legs in ordinary use,

and, third, to provide av leg whose construction is so simple as to be within the reach of one unskilled in the ordinary mechanic arts.

Referring to the drawings, Figure l is the upper portion of the leg, broken away at the center to show the various layers of which it is composed. Fig. 2 is a longitudinal section of leg, showing edges of the different layers.

I attain the objects of my invention by an artificial leg constructed as follows: A plaster cast of the stump to be fitted is taken, which is elongated by an addition to the lower end, so that the Whole shall be in length and shape like the natural limb to be represented. Over this ca-st of stump thus elongated is stretched a basis-membrane of sheepskin or other yielding substance, and so applied as to be made to conform to all its inequalities of surface. Upon this basis-membrane is placedalayer of thin strips of wood, arranged longitudinally, which are forced down by pressure and made to conform accurately to its surface and secured to it by glue or cement. (The pressure is produced by winding a copper wire around the leg and two pieces of wood on opposite sides and driving wedges between the two piecesof wood.) This layer of wood is further secured by the next layer, which is a compact winding of cane applied with pressure and secured to the previous layer by glue or cement.

to the previous one.

Over the v cane is stretched a layer of thin leather likewise secured by glue or cement. These layers are repeated in their order until the required strength is attained, each layer being forced down by pressure so distributed as to produce perfect conformity of surface The plaster cast is then broken up and removed and the surface inside a-nd outside rendered impervious to moisture by a coating of some Awater-proof application.

I am aware that prior to my invention artificial legs have been constructed of concentric layers of wood secured to each other by cement. concentric layers fastened by cement as entirely new.

Vhat I therefore claim isl. The improved method hereinbefore described of making artificial legs, the same consisting in making a plaster cast of each individual stump to be fitted, elongating or extending said cast by adding material to its lower end, the said cast and its extension constituting a former, the upper part of which is a fac-simile of the form of the individual stump to be fitted, then fitting a base layer of leather or other suitable iiexible material closely to said former, said base layer conforming accurately to all the inequalities of the surface of the former, and then adding one or more inclosing-layers of suitable material and interposing glue or cement between each layer, including the base layer and the next, the layers being conformed exactly to I therefore do not claim the use ofthe shape ofthe former before the cement l hardens, and finally breaking the former and removing it after the cement has hardened, the said layers constituting a rigid laminated hollow leg, the interior of which accurately conforms to all the inequalities of the said cast made from the individual stump to be fitted, as set forth.

2. An artificial leg in which are combined a base layer of leather or other suitable flexible material accurately conformed at its upper portion to the inequalities of a cast of the individual stump to be fitted and an inclosing-layer composed of wooden strips closely fitted and conformed to the exterior of the base layer and united thereto by glue or cem- IOO ent, the grain of said strips extending lengthwise of the leg, as set forth.

Au artificial leg in which are combined a base layer of leather having its upper portion formed to accurately t a east of the individual stump to be fitted, a layer of wood strips fitted closely to and glued upon the exterior of lthe said base layer, the grain of the Wood extending longitudinally of the leg, and a Wrapping-layer composed of strips of fibrous material, as cane, Woundv about the Wood layer and glued thereto, the grain of the ibrous material extending orosswise of the grain of the Wood, as set forth.

4. The improved artificial leg herein described, the same consisting of a base layer of leather having its upper portion formed accurately to lit the inequalities of a east of the individual stump to be fitted and a plurality of series of superposed layers inclosing said base layer, each series being composed of a layerof wood, a layer of cane, and a layer of leather connected by glue or cement, the Wood layers being composed of strips the grain of which extends lengthwise of the leg, and the cane layers of strips Wound upon the wood layers with the grain extending across that of the Wood layers, the outer layer of the outer series of layers being of leather, as Set forth.

PHILIP CHESTER PORTER. Witnesses:

CHAs. E. FRENCH, MARION W. PORTER. 

